Dungeon Overlord: Monster Girl Harem! - Chapter 104: The Lizards Dirty Deal!

As a precocious child, Lycoris suffers from a strange sense of deja vu. On the day her father told her about her fiancé, she realizes that her fiancé was a character from an otome game she once played in a previous life.

In my last life, it was difficult to have a child. In this life, I was given three radish heads as soon as I passed it, and there was an extra head. I thought my husband was a rough guy, but I didn’t expect a tough guy to have tenderness.

- Description from novelbuddy

After the ‘100-Year War’ between the Necromancers and Priests, an all-time genius who’ll shake the power structure was born. “Am I a rare case or something? Do I have talent?” A potential beyond all imagination. He obtained his father’s undead army and entered the great Necromancer school of Kizen that divided the continent. Geniuses are geniuses, even when gathered among the elites. The research community was flipped on its head by the appearance of a new case. Professors wouldn’t leave him be alone, wanting to make him study directly under them. Officials from all over the kingdom and heads of organizations fidgeted over whether to scout him. “Professor! When can I make a Lich?” “Gimme a break. How talented are you? You’re crossing the line, honestly.” A genius among geniuses had appeared.

God plucked one of his creations from his first Earth and gave him a second chance in another one of his Earths...surprise it is in DxD! Now reincarnated as a perverted side character how will our poor protagonist handle his new identity? Well he probably wont make the choices you will want him to, that's for sure!